There is a need to better assess both positive and negative late consequences of the various anti-HIV therapies administered to children. This study is designed to collect prospective, longitudinal data to identify 1) late outcomes and consequences related to HIV disease progression, treatment or prophylactic intervention, and/or interaction of HIV disease and therapy and 2) late treatment effects among perinatally treated infants proven to be uninfected. Data will include history, quality of life assessment, physical exam, neurocognitive testing, clinical and laboratory evaluations, morbidity, and mortality. The study will last until the child reaches his/her 21st birthday or is lost to follow-up.